Which of the following options contain systems that possess both kinetic energy and potential energy?
1. A boy standing on the top of a building.
2. A descending airplane moving with a velocity v.
3. A book placed on the table.
4. An apple on a tree.

if you answer my question i will answer yours

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.